So is it this easy? (Roman Shades)

So I think I want to go with roman shades for my new home. They look nice and clean and they appear to have some of the best insulation values for a window treatment.

Going online it seems like it would be easy to actually make myself so long as I had someone that is proficient at using a sewing machine...

Here is my plan:

For each window I want two roman shades. A white shade that will let sunlight in but give some privacy/insulation and a blackout one that will be a darker color.

My thought is have the fabric (any recommendations for the fabric I should use?) and have 4mil plastic inbetween to provide additional insulation/wind barrier. Then just sew the three together all around and also sew them together at the points where I will have fabric to connect the wooden dowel. Then buy a hardware kit that would have the cords, hooks etc.

Is this harder than it seems?

Any recommendations from anyone who has done this?

Would it be cheaper in the long run just to have a company come in and do this for me?